Himeanwhile I de-installed PDFE and re-installed it again. Installation goes well but when I select a folder for PDF import PDFE closes immediately and cannot be restarted again (unless another de-installation / re-installation process will be initiated). Error message below does not show up again.Any thoughts, please?

Check with the Windows Event Viewer if there is any application error related to PDFExplorer.exe. To easily find all the events specific to the PDFExplorer.exe process you may create a custom view, with this XML filter:

You may also try with the process monitor tool, to log all the registry and file system activity generated by the PDFExplorer.exe, so I can check what may be causing this issue.Just set a filter to monitor only the activity generated by the process named PDFExplorer.exe, enable the Show Registry and Show File System activity toolbar buttons, (as depicted in the attached screenshot) and then run the PDFE until it fails. Take a screenshot of the tool showing the last logged lines or, even better, save the log to a file, zip it, and attach it here to a forum reply.